Year	Percent
1995	19.49776
1996	20.12843
1997	19.81503
1998	20.52135
1999	20.85849
2000	20.0439
2001	19.95028
2002	20.43915
2003	20.62192
2004	20.60107
2005	21.0672
2006	20.83755
2007	20.02956
2008	19.39492
2009	18.0413
2010	18.11283
2011	17.91762
2012	17.95507
2013	18.00613
2014	18.1782
2015	18.49886
2016	18.55501